Final answer:
The career agency distribution system uses agents who primarily, if not exclusively, represent one insurer.
Step-by-step explanation:
The correct statement regarding the career agency distribution system is D. It uses agents who primarily, if not exclusively, represent one insurer. The career agency distribution system is a structure in which agents are hired to represent a specific insurer and sell their products. These agents may work exclusively for one insurer or primarily represent one insurer while also selling products from other insurers. This system is different from the other options mentioned, which describe the different types of agency systems within the career agency distribution system.